Geomechanics of Coal Seams E-Book

Matthieu Vandamme

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Serie: ISTE Invoiced
• Sprache: Englisch

Seitenzahl: 422

Veröffentlichungsjahr: 2025

Beschreibung

Geomechanics of Coal Seams explores the evolving role of coal, transitioning from a historically criticized energy source tied to the Industrial Revolution, to a material with the potential to play a significant role in achieving net-zero greenhouse gas emissions. Traditionally used as raw material, coal now serves as a reservoir for natural gas or carbon dioxide storage, offering a path toward reducing global greenhouse gas emissions. Despite its promise, challenges remain, particularly regarding its geomechanical behavior.

This book delves into the unique properties of coal, covering everything from geological foundations to numerical modeling. Aimed at students, researchers, and engineers, the book provides valuable insights applicable to other microporous materials.

Leseprobe

SCIENCES

Mechanics, Field Director – Gilles Pijaudier-Cabot

Geomechanics, Subject Head – Gioacchino Viggiani

Geomechanics of Coal Seams

Coordinated by

Matthieu Vandamme

Jean-Michel Pereira

First published 2025 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc.

Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the undermentioned address:

ISTE Ltd27-37 St George’s RoadLondon SW19 4EUUK

www.iste.co.uk

John Wiley & Sons, Inc.111 River StreetHoboken, NJ 07030USA

www.wiley.com

© ISTE Ltd 2025The rights of Matthieu Vandamme and Jean-Michel Pereira to be identified as the authors of this work have been asserted by them in accordance with the Copyright, Designs and Patents Act 1988.

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s), contributor(s) or editor(s) and do not necessarily reflect the views of ISTE Group.

Library of Congress Control Number: 2025932187

British Library Cataloguing-in-Publication DataA CIP record for this book is available from the British LibraryISBN 978-1-78945-201-3

ERC code:PE10 Earth System SciencePE10_5 Geology, tectonics, volcanologyPE10_10 Mineralogy, petrology, igneous petrology, metamorphic petrology

IntroductionWhy a Book on the “Geomechanics of Coal Seams”?

Jean-Michel PEREIRA and Matthieu VANDAMME

Navier, ENPC, CNRS, Institut Polytechnique de Paris, École nationale des ponts et chaussées, Université Gustave Eiffel, Marne-la-Vallée, France

In the collective consciousness, coal is a material closely associated with the industrial revolution of the 19th century. Today, in an era of environmental urgency, it is rightly criticized as a particularly polluting energy source that emits significant amounts of greenhouse gases. So why a book on the “geomechanics of coal seams?”. Because, by focusing on the geomechanical aspect, we consider coal as a reservoir rock rather than as an energy source. The targeted applications are natural gas production (recently designated as energy transition by the European Union1; a coal gas extraction project in Moselle has just been granted by the French government2) and, potentially, underground carbon dioxide storage, although pilot projects in recent years have underscored the challenges of using coal seams for this purpose. In both applications, the reservoir undergoes evolving mechanical stresses during its operation. These stresses must be managed to ensure optimal and safe exploitation. However, coal seams possess specific characteristics that make their hydromechanical behavior significantly different from that of other reservoir rocks. Controlling these stress variations therefore necessitates the application of geomechanics, with “geomechanics” referring to the study of the hydromechanical behavior of geological materials and reservoirs.

Figure I.1.Keyword co-occurrence network constructed3 from a corpus based on the presence of the terms “coal seam” or “coalbed” along with “production” or “storage”. The network reveals four groups (clusters) of keywords. The green cluster pertains to topics related to methane and carbon dioxide, highlighting the presence of keywords associated with adsorption/desorption and swelling.

These two applications are reflected in the keyword co-occurrence network shown in Figure I.1, which indicates that the keywords most frequently associated with scientific studies addressing production or storage issues in coal seams include “methane” and “carbon dioxide” as prominent terms.

The increasing interest in the study of coal as a reservoir rock is clearly demonstrated in Figure I.2, which illustrates the annual number of scientific publications focusing on coal seams. This figure also reveals that the scientific community is more focused on coal seams for production purposes (including both coal and natural gas) than for storage (carbon dioxide).

Figure I.2.Number of scientific articles published per year mentioning the term “coal seam” or “coalbed”.

Beyond its practical applications, the study of coal seam geomechanics holds significant scientific interest. Like other reservoir rocks (such as carbonates) or natural materials (like soils or wood), coal is a complex material due to its genesis, heterogeneity and multi-scale nature, requiring the use of advanced tools for detailed study and modeling. However, coal also exhibits unique characteristics: one being the adsorption–deformation coupling due to its microporous nature; another being that it is a naturally fractured material.

This book, dedicated to the geomechanics of coal seams, is divided into seven chapters. Chapter 1 provides a detailed introduction to coal, including its genesis, characteristics, resources, uses and its role in the context of climate change. Chapters 2 and 3 are predominantly experimental, as experiments are essential for characterizing the geomechanical behavior of the material. Chapter 2 focuses primarily on the hydraulic properties of coal, as these transport properties within the reservoir are key during injection or production processes, emphasizing the fact that coal is a fractured material. Chapter 3 is dedicated to the sorption and poromechanical properties of coal. These sorption properties allow coal to contain large volumes of gas, while the poromechanical properties enable the expression of the coupling between fluid pressures, stresses and deformations. Chapters 4–7 focus on modeling at different scales. Chapter 4, the first modeling chapter, introduces material modeling at the continuous medium scale and the poromechanical formalism. Chapter 5 delves into the finest scale of the material, presenting molecular simulation methods in connection with the continuous medium models introduced in the previous chapter. In contrast, Chapter 6 explores larger scales, detailing finite element methods that, based on the constitutive equations introduced in earlier chapters, enable the simulation of reservoir exploitation. It also explains how to account for fault presence in calculations. Finally, Chapter 7 presents a numerical homogenization method (a “squared” finite element method) that enables simulations at the scale of naturally fractured material, building on finer scale simulations of fractures and the coal matrix.

This book is intended for students, engineers and researchers interested in the subject. Although the chapters are naturally centered on coal, the concepts, methods and tools presented are applicable to other materials. The experimental methods discussed in Chapters 2 and 3 can be applied to other rocks and porous materials. The poromechanical approach introduced in Chapters 4 and 5 is relevant for studying the mechanical behavior of any porous material in the presence of fluids. Moreover, the molecular simulation methods (Chapter 5), finite element methods (Chapter 6) and “squared” finite element methods (Chapter 7) are generic techniques in materials science and solid mechanics. We therefore hope these chapters will spark interest beyond the specific field of coal geomechanics.

We sincerely thank all the contributing authors for accepting our invitation to participate in this book.

Notes

1

Commission Delegated Regulation (EU) 2022/1214 [Online]. Available at:

https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32022R1214

.

2

Decree of November 20, 2023, granting the concession for conventional liquid or gaseous hydrocarbon mines, known as the “Concession de Bleue Lorraine” (Moselle), to the company La Française de l’Énergie SAS:

https://www.legifrance.gouv.fr/jorf/id/JORFTEXT000048443696

.

3

The SCOPUS queries, covering all indexed documents and conducted in July 2022, are as follows: TITLE-ABS-KEY ((coalbed OR “coal seam”) AND (storage OR sequestration OR production OR recovery)), labeled “production or storage,” returned 8,030 documents.

TITLE-ABS-KEY ((coalbed OR “coal seam”) AND (production OR recovery)), labeled “production”, returned 7,244 documents.

TITLE-ABS-KEY ((coalbed OR “coal seam”) AND (storage OR sequestration)), labeled “storage”, returned 1,810 documents.